A tent that has been sprayed with foam insulation is pictured at the Army National Training Center in Fort Irwin, California July 31, 2008. Tents with this foam insulation which are air-conditioned and used as sleeping quarters, are being used in forward operating bases in use in Iraq, Kuwait and Afghanistan. The foam insulation saves almost 180,000 gallons of fuel per day, which is used to generate power to run the HVAC systems. The U.S. military has a history of fostering change, from racial integration to development of the Internet. Now, Pentagon officials say their green energy efforts will help America fight global warming. Picture taken July 31, 2008. REUTERS/Fred Prouser (UNITED STATES)
REUTERS/FRED PROUSER